1. Field of the Invention
The present invention relates to an image forming apparatus which includes a plurality of exposure units using, for example, a light-emitting diode or LED, electroluminescent device, etc. as a light source for forming an electrostatic latent image on a photoconductor.
2. Description of Related Art
Typically, printers and digital copying machines of the LED type, as image forming apparatuses, are configured to emit LED light corresponding to image data, which is created from source data as a target to be printed, onto a photoconductor to form an electrostatic latent image on the photoconductor. Toner is supplied from a process unit to the electrostatic latent image on the photoconductor to form a toner image. The toner image is then transferred onto a sheet (of paper, for example) and fixed thereon by heat.
This type of image forming apparatus should have an LED unit for emitting LED light arranged close to an opposed photoconductor, and thus a multicolor image forming apparatus of the LED type, in particular, typically includes a plurality of LED units provided such that each LED unit is arranged between adjacent process units. Therefore, the apparatus configured in this way is unable to realize easy-replaceable process unit configuration as disclosed in JP 2006-98772 A (see FIG. 2; the corresponding U.S. Patent Application is laid open under Publication No. US 2006/0067734 A1) wherein the process units of an image forming apparatus are replaceable in a simple operation of pulling frontward the process units out of the image forming apparatus.
On that account, for example, JP 10-187002 A (see FIG. 1) discloses an image recording apparatus wherein an upper cover to which LED units are mounted, is opened upwardly to a position in which the upper cover forms an angle of approximately 90 degrees with a main body of the apparatus so as to form an opening at an upper side of the main body of the apparatus and each process unit is removed upward through the opening for replacement.
In order to swing the large upper cover with the LED units mounted thereto open through a full 90 degrees, an ample space should be provided behind and/or above of the apparatus. Thus, the apparatus would disadvantageously suffer from severe limitations on its installation location. Moreover, as is often the case with such an apparatus, an image reader unit for reading image data may be mounted on the top of the apparatus, and in such an instance the upper cover is provided integrally with the LED units and the image reader unit, which would disadvantageously render the upper cover rather heavy, unstable, and detrimental to its handleability.
The present invention has been made in an attempt to eliminate the above disadvantages. Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above.